INCORPORATE RESEARCH ON SCRATCHING AND UNIAXIAL TENSION OF THREE-DIMENSIONAL MICROCONSTRUCTION SIMULATION BASED ON MOLECULAR DYNAMIC
A method of incorporating research is proposed on scratching and uniaxial tension based on molecular dynamics (MD) with embodied atom method (EAM) for single copper in this paper. The process of tri-pyramid diamond tool scratching the single copper on the (010) plane is simulated under different penetrated depths. The details of scratching process and uniaxial tension are depicted in atomic view. The phenomena of heal-up surface, dislocations and burr are shown after the workpiece is scratched and the principle of that is attempted toanalyze. The defects of the surface and subsurface of the workpiece scratched are represented and analyzed by the perspective of dislocations and radial distribution function (RDF). Whereafter the uniaxial tensile simulation of the “real workpiece after scratching is performed. The mechanism of deformation and the details of change under the uniaxial load are analysed through the stress-strain curve that is combinedwith the perspective of atom. From simulations results, it is found that the dislocations only occur on the surface and subsurface of workpiece at the small scratching depth, while the dislocations are nucleated and emitted in front of tool and beneath the tool under the deep scratching depth. Dislocations disappear when they propagate to the surface. After the tool escapes the workpiece, the atoms on surface of the workpiece scratched heal up to some extent by the inter force of atoms, while some of the pile-up atoms on surface of tool are attracted backwards surface of workpiece, then form the burr, and others of those atoms are absorbed on the tool’s surface. The number of defects from surface and inner of workpiece increase when the scratching depth is doubled. The order of crystal decreases, especially long rangeorder. It is shown that the penetration depth into the workpieceduring scratching affects both surface pile-up and residual defect generation that is important in assessing the change of material properties after being scratched. In the process of the simulation of uniaxial load, the yield stress decrease with the increasing depth of cutting, and dislocations are nucleated at the bottom of groove, especially at the position where the tool escaped nearby burr firstly, and dislocations at ～45° are observed. It shows that groove is the source of the dislocationsaroused. The break-up point is near to the middle of workpiece with increasing depth with groove.
MD scratching tension incorporation simulation Real workpiece
Yingchun Liang Jiaxuan Chen Qingshun Bai Yulan Tang Mingjun Chen
Harbin Institute of Technology Haerbin 150001, China Shenyang Jianzhu University Shenyang 110168, China
国际会议
海南三亚
英文
2007-01-10（万方平台首次上网日期，不代表论文的发表时间）